Pulmonary embolism during compression US of the lower extremity

To the author's knowledge, occurrence of pulmonary embolism during performance of compression ultrasound (US) of the lower extremity has not previously been reported in the radiology literature. The author describes a case in which pulmonary embolism was witnessed during compression US of venous thrombosis in a superficial femoral vein of a 64-year-old man. The embolism was documented with perfusion lung scanning.